(1) Field of the Invention
The present invention relates to a frequency tunable magnetostatic wave resonator which utilizes magnetic spin resonance of yttrium iron garnet (hereinafter referred to as YIG) film. More specifically, the invention relates to a wide-band frequency tunable integrated resonator that is produced from a thin YIG film grown on a gadolinium gallium garnet (hereinafter referred to as GGG) substrate by photolithography, the wide-band frequency tunable integrated resonator being adapted to be mounted in a small metallic package.
(2) Description of the Prior Art
As a magnetostatic wave resonator utilizing the magnetic spin resonance of YIG, the prior art has shown a small resonator in which a magnetic bias field is applied in the direction of YIG film to utilize magnetostatic waves that propagate through the YIG film (see IEEE, Ultrasonic Symposium, 1984, pp. 164-167).
The above known resonator resonates on a 12-GHz band using a 4 mm.times.1.4 mm square YIG/GGG chip as shown in FIG. 2.
In this case, however, it is not allowed to place on the chip a transducer which excites the magnetostatic waves, making it difficult to unitize the whole structure and to mount it in a small package. Further, consideration has not been given in regard to bringing the chip into alignment with the transducers.
The object of the present invention, therefore, is to realize a resonator which can be fabricated maintaining high precision and which requires a magnet of a small size.